[gl4java-usergroup] Suggested tesselator fix

[Pepijn V. E. <pep...@lu...>]

I noticed that only one set of callback functions can currently be
defined per context. I have made a simple fix for this. (Only tested
with the tesselators, not yet with quadrics and nurbs but should work as
well). I've changed the following:

1. Added a void pointer curCbObj to GLCallbackHelperJNI.c
2. FindCallBackNode now also checks if cbn->this->cb_obj!=curCbObj
3. Every glu tesselation function sets the curCbObj to the value that it
receives as a parameter.

Does this sound like a good fix?

Pepijn Van Eeckhoudt